The present invention relates generally to the severing and aspirating of rapidly traveling filamentary material during, for example, the high speed winding of the filamentary material onto bobbins or spools to form packages of filamentary material. More particularly, it relates to an aspirating cutter which severs the filamentary material as it travels at high speed (say 200 mph) during removal of a full package, and aspirates the severed filamentary material to a remote source (e.g., to waste).
The manufacture of man-made or synthetic filament yarns is typically performed by extruding a molten polymer, such as polyester, polyamide, etc., through hole(s) in a spinneret and then cooling the filament(s) thus formed. Thereafter, the filaments may be gathered together to form a multi-filament yarn and, possibly after further treatment, are wound onto a tube so that a yarn package is formed.
Winding of the yarn is performed mechanically by winders which rotate one or more packages to wind-up the yarn while traversing the yarn along the package axis to achieve a uniform thickness of yarn being wound.
A doffing/donning operation (i.e., replacement of the yarn packages with empty tubes on the winder) is often performed manually by an operator who (i) severs the yarn, (ii) stops the rotary drive to the packages, (iii) replaces the packages with empty tubes, (iv) re-establishes the rotary drive, and (v) rethreads the yarn onto the empty tubes. Severing of the filamentary yarn has been conventionally performed with scissors while the inlet of a suction or aspirator gun is held against the yarn at a location above the point of severing. Once the yarn is severed, the tail end is wound onto the yarn package, while the newly formed leading end is sucked into the aspirator and fed to a waste collector. The suction gun is then placed onto a holder while the yarn packages are being replaced by empty tubes. When the empty tubes attain full speed, the operator manipulates the suction gun to attach the yarn to the rotating tubes so that a subsequent winding operation may begin.
Severing of the yarn has also been performed with an aspirating cutter of the type manufactured by Slack & Parr, Inc. of Charlotte, N.C. (model 4F-11). This cutter comprises a handle in which is disposed an aspirator nozzle for creating a vacuum in a suction tube which projects forwardly from the handle. This suction tube is surrounded by an outer tube which extends from the handle and is reciprocably driven by a trigger-actuated fluid motor in the handle. The outer tube includes a laterally opening slot positioned slightly rearwardly of the forward end of the outer tube. In practice, an operator manipulates the forward end of the waste gun laterally to cause the yarn to enter the slot in a lateral direction. Upon actuation of the trigger, the outer tube is driven longitudinally rearwardly, whereby the slot travels past the front end of the suction tube. The front edge of the slot is sharp, so that the yarn is severed. Upon being severed, the yarn becomes entrained within the suction flow of the suction tube. The outer tube is then moved forwardly to prepare the device for cutting and aspirating another filament while the previously cut yarn continues to be aspirated. This arrangement may be described as an in-line aspirating cutter since the cutting elements and suction tube are essentially aligned longitudinally. Such an aspirating cutter is suitable when the yarn is nearby and readily accessible. It can, however, be difficult to utilize when dealing with remote yarn, e.g., filaments located six or seven feet from the operation in areas of limited accessibility. The difficulty in laterally maneuvering the end of the cutter at that distance to engage a yarn will be appreciated, especially in cases where there exists little maneuvering space. Accordingly, it takes longer for an operator to capture the yarns, thereby reducing the quantity of winders that can be serviced by each operator, i.e., more operators are required.
Another type of side-entry, in-line aspirating cutter is described in U.S. Bunting, Jr. et al U.S. Pat. No. 3,175,290 issued Mar. 30, 1965.
Aspirating cutters have been proposed which include a forwardly facing slot so that the yarn can be captured in response to longitudinal motion of the cutter (e.g., see U.S. Pat. Nos. Flower et al 3,793,917 issued Feb. 26, 1974; Corl 3,915,398 issued Oct. 28, 1975; and Burysek et al 3,948,452 issued Apr. 6, 1976). In such arrangements, the suction manifold is typically spaced laterally of the slot, whereby the dimensions of the cutter are so large as to render the cutter cumbersome to manipulate in areas of low-accessibility.
In the afore-mentioned Flower et al patent, the cutter is of the rotary type having telescoping, relatively rotatable tubes wherein a cutter edge travels in a rotary path across a yarn-receiving slot. The use of suction air is disclosed at column 2, lines 35-59 of that patent, but without suggestion that the suction would be disposed in other than the common laterally spaced relationship. Moreover, the arrangement of the telescoping tubes in Flower et al would be undesirable in a cutter of the in-line flow type wherein the cutter must be able to cut one yarn while continuing to aspirate a previously cut yarn. This is so, because the rotary tube of Flower et al would likely contact and tension the previously cut yarn. As noted earlier, excessive tensioning of aspirating yarn can cause the yarn to break.
Thus, it will be appreciated that in instances where remote yarns are to be cut in spaces affording little maneuverability, it is desirable that the barrel of an aspirating cutter can be compact and capable of receiving the yarn during longitudinal motion. It is also desirable that the aspirating cutter be capable of cutting one or more additional yarns without cutting or disturbing the previously captured yarn(s). In this regard, excessive tensioning of the yarn can produce yarn breakage, whereupon the filaments emerging from the spinneret will wrap around the godet roll located above the winder and require manual untangling.